Sciencemadness Discussion Board

Brewing Homemade Vinegar to Make Acetic Acid

CwisGons - 17-9-2021 at 20:36

I have been making ethanol by just brewing sugar wash with yeast in a 5 gallon container, similar to NileRed's video(just bigger):
https://www.youtube.com/watch?v=txm7eu8KxVI

I would like to try brewing my own vinegar to get cheap acetic acid. Would this be possible and more importantly economical? If so, do you guys have any suggestions to maximize concentration? Is there a precedent for this? I was thinking of doing the same sort of thing.

I will try making sugar wash, and then add some mother of vinegar into a 5 gallon jug, and just let it sit. I would get mother from some cheap apple cider vinegar. How does this sound? Do you think that I should add yeast?

Sulaiman - 17-9-2021 at 21:11

I had a go,
Fermentation is MUCH slower than brewing ethanol - many months,
and it goes through some rather smelly stages,
so not to be done indoors is my advice.

Worth doing as an experiment
but 99.9% acetic acid is cheap.

I see no need for yeast.

unionised - 18-9-2021 at 10:51

You need to ensure that the bacteria also have access to air so that they can oxidise the ethanol.

I once wondered if you could use a garden "water feature" to do this. A solar powered one would cost more initially, but have low running cots.

Nonexistent - 18-9-2021 at 19:54

If you could source some acetobacter, you'd be set, and as mentioned above, aeration is needed. Yeast isn't needed unless you still have unused sugars you want to be fermented into ethanol.

It's not really worth it except as some fun/experiment because distilling is near impossible and making the acetic acid at a higher percentage is a pain, you're better off buying whatever commercially available, 8-10% stuff is at your local grocery store for cheaper, or sourcing a stronger percentage elsewhere.

zed - 19-9-2021 at 23:50

I can't seem to stop it. Apples fall from my Ashmead's Kernal Apple tree, they bruise, and within a day or two, they are mushy, brown, and reeking of vinegar.

unionised - 20-9-2021 at 03:20

It's worth it if you want a few gallons of dilute acid to descale your swimming pool or something.

It's not a great place to start if you want clean acetic acid.
If you live somewhere where the climate will let you freeze the stuff easily, that will increase the concentration to a useful extent.

stamasd - 22-9-2021 at 11:33

It is of course possible. Economical? no.
I am making my own vinegars, for food purposes. It is a slow process even with a well established mother-of-vinegar. 1L of ~8% ethanol takes about 2 months for full conversion.
Also keep in mind that what you get will not be pure by any definition of "purity" - you will have mixed in side products from the initial fermentation, side products from the second fermentation, organic debris from the mother-of-vinegar etc.

macckone - 23-9-2021 at 08:28

generally vinegar is made via fermentaion.
due to economy of scale it is cheaper to buy it that make it.
basic procedure is ferment alcohol using a standard wash, dilute to 5% if the wash is more concentrated.
add mother of vinegar and aerate.
wait months, then distill.

If you need a concentrate, convert to sodium acetate then from dry powder, add concentrated sulfuric acid and distill.
you will get charring of impurities and some of the acetate, but it should be nice and dry.
if it isn't dry enough, redistill with acetic anhydride, P2O5 or sulfuric acid.

karlos³ - 23-9-2021 at 13:20

Get a fruit fly.
A single Drosophila is sufficient, they usually have more than enough Acetobacter at their feet.

S.C. Wack - 23-9-2021 at 14:01

Quote: Originally posted by macckone  
add mother of vinegar and aerate.

wait months


These are separate.

Y'all speak of farm, Orleans process ($), and authentic ($$$) balsamic grape vinegars, boutique products not representative of what is sold. Methods where the conversion is long, or where it's short but the product is then aged, would be subject to more difficulties in inexperienced hands.

That which is actually bought as vinegar (in countries where vinegar is filtered bacterial broth, by law) is converted from alcohol to acetic acid in a day or two, since a long time ago (Boerhaave 1732, Schutzenbach 1823). Their packed towers may still be in use, but some variation of unsupported aeration (frings.com) is the likely source of commercial bacterial acid.

PS this is biochemistry. Ozone or Pt would be organic chemistry.

[Edited on 23-9-2021 by S.C. Wack]

macckone - 24-9-2021 at 07:24

SC Wack,

The acetobacter available to the home brewer are generally not the fast strains.
Most are for a balsamic process.
I am certain the fast strains can be bought but those aren't what I have access to.
The main difficulty is keeping everything sterile while aging but alcohol and acetic acid generally kill intruders so it isn't as much of an issue as you would expect.

S.C. Wack - 24-9-2021 at 15:22

Special strains weren't available 100 years ago either, much less 200. One doesn't need special bacteria, one needs to do the process correctly...but y'all don't seem interested in any but the most primitive methods.

There are various ways for vinegar to go bad, mentioned in any suitably detailed text on the subject.

[Edited on 24-9-2021 by S.C. Wack]

macckone - 27-9-2021 at 06:37

SC Wack,

Oxidation over a copper oxide packed column in the presence of oxygen, is great for industry.
but it requires flow pumps and proper packing not to mention proper fire protection, it can go boom.
the same with the schutzenbach process except it is much less likely to go boom.
The difference between the two is the schutzenbach process uses acetobacter to establish an enzyme base.
It still takes about a week and it is much more complicated than add acetobacter to solution, bubble air or otherwise oxidize.
The industrial process is usually heated and is instant but doesn't make a food grade product due to a wide range of impurities and no flavor.

The hromatka process is easier for a home process. It is simply bubbling air into the mix.
It still takes a while though. It isn't the simple add mother of vinegar and let sit.

unionised - 27-9-2021 at 09:58

Quote: Originally posted by macckone  
SC Wack,

Oxidation over a copper oxide packed column in the presence of oxygen, is great for industry.

Yes it is.
But it's nothing to do with what's under discussion here.
Copper would dissolve in vinegar and kill the bugs.

S.C. Wack - 27-9-2021 at 16:57

Quote: Originally posted by macckone  
SC Wack,

Oxidation over a copper oxide packed column in the presence of oxygen, is great for industry.
but it requires flow pumps and proper packing not to mention proper fire protection, it can go boom.
the same with the schutzenbach process except it is much less likely to go boom.
The difference between the two is the schutzenbach process uses acetobacter to establish an enzyme base.
It still takes about a week and it is much more complicated than add acetobacter to solution, bubble air or otherwise oxidize.
The industrial process is usually heated and is instant but doesn't make a food grade product due to a wide range of impurities and no flavor.


They didn't use pumps 200 years ago either.

It takes a week to establish bacteria on fresh packing. Once established, a mixture of finished vinegar and alcohol source (+ nutrients if we're talking about distilled white vinegar) is added at the top of the column every day. And vinegar of <0.5% ethanol content is taken off the bottom, every day.

It's not more complicated than a barrel packed with wood shavings and holes for air.

The industrial process is not heated, because the reaction is already exothermic and further heating is bad. The industrial process does make a food grade product, because that's where store bought vinegar comes from.

It takes a day to establish bacteria in a Frings acetator. Another day to acclimate the bacteria to production conditions. This bacteria is everywhere as I found out when I made my first sugar wash at 15. Its growth habit is self-adjusting if changed gradually. From then on, even the modern submerged culture is very similar to supported, with half the vinegar poured off as product and half retained and mixed with more alcohol. Note that 8 liters does not refer to the actual liquid volume:

The PILOT-ACETATOR 8 L is one of our smallest vinegar fermenters, with an annual capacity of approx. 840 liters of vinegar. With this system it is possible to produce approx. 2 - 3 liters of vinegar per day. This system also works automatically depending on the configuration.

macckone - 27-9-2021 at 21:14

unionized,

Yes, those two are not compatible.
One is a purely chemical process while the other processes are biochemical.

Copper does not dissolve easily in acetic acid.
The copper oxidation process is gas phase, which makes it even harder.
There is a wide range of catalysts that will work but copper is by far the cheapest.

It would be interesting to see how much copper actually dissolves in a liquid phase reaction.
There are things in there other than acetic acid. And the copper oxide will react in the liquid phase.
One of the questions about vinegar making is how much of the late stage oxidation is bacterial and how much is remaining enzymes (ADH and ALDH).

In traditional balsamic vinegar production, the enzymes do the work long after the yeast and bacteria are dead.
Quick homemade vinegar takes a couple of months. Traditional balsamic vinegar is 12 years to be certified.
Hromatka process vinegar, is a week or two from the mash. The mash takes a week or so for 5%.
schutzenbach process vinegar is going to be a week or two as well.
If you have the super acetobacter strains and use the Hromatka process, it will be done in a day or two.

unionised - 28-9-2021 at 01:29

Quote: Originally posted by macckone  
unionized,

Yes, those two are not compatible.
One is a purely chemical process while the other processes are biochemical.

Copper does not dissolve easily in acetic acid.
The copper oxidation process is gas phase, which makes it even harder.
There is a wide range of catalysts that will work but copper is by far the cheapest.


That is still nothing to do with making vinegar.
We know that we can buy acetic acid made by industrial oxidation of ethanol or C2 hydrocarbons or whatever.
But that's not the point.

Do you not understand that vinegar is, by definition, a fermentation product?


Incidentally, by an odd coincidence I'm making copper acetate. Coper oxide dissolves nicely in the "non brewed condiment" I'm using.
It's 4.5% acetic acid in water.
never been near a fermentation.

happyfooddance - 28-9-2021 at 12:15

S.C. Wack pretty much laid it out. You might want to look at the Pasteur method, it might work out better for you but is usually much slower. I am not going to add much else except to say that if you are going to attempt to freeze separate (to then perhaps distill or something), then you will want to run your sugar lean, in other words use as little sugar as you need to keep the bacteria happy and producing acetic acid. Also activated carbon is great at capturing acetic acid vapors, and the carbon can be dry distilled to get the acetic acid back.

macckone - 28-9-2021 at 12:41

unionized,

yes, copper oxide is readily dissolved in liquid phase acetic acid regardless of source and the concentration doesn't have to be high. Gas phase is a different story. And raw copper is pretty immune at low concentrations.

The original topic is making acetic acid from sugar via fermentation.
the questions posed were:
can it be done
is it economical

The answers are yes and no.

There are some additional question such as will just letting it sit work.
Answer is yes, but it takes forever.

Maximizing concentration would require the traditional balsamic process which can get up to 30% but it takes 12 years give or take and relies on enzymatic action and uncatalyzed oxidation after the yeasts and acetobacter have died.

We have covered many ways to make acetic acid. At the end of the day it is cheaper and easier to buy it.
Unless you want boutique stuff or just the personal challenge.

I pay $1.49 for a gallon of 5%.
The non-DOP balsamic stuff is still pretty pricey but it doesn't take much and it isn't authentic but it is made in a a traditional manner ($40 / bottle). The fake stuff is still not cheap ($15 / bottle).
The authentic stuff is very expensive. DOP is $1 a ml.

But the question was acetic acid and the industrial oxidation is still a good method for that.
I have the stuff to make an industrial oxidation setup, but haven't bothered.
It is the same as the acetaldehyde (does not technically require O2 but it improves yield) but more O2.
The acetaldehyde is easily oxidized with air especially at high temperature.

S.C. Wack - 28-9-2021 at 14:17

Quote: Originally posted by macckone  
relies on enzymatic action and uncatalyzed oxidation after the yeasts and acetobacter have died.


Good luck finding a reference for that...
Quote: Originally posted by macckone  
Hromatka process vinegar, is a week or two from the mash. The mash takes a week or so for 5%.
schutzenbach process vinegar is going to be a week or two as well.
If you have the super acetobacter strains and use the Hromatka process, it will be done in a day or two.


How then do you explain the claim of yearly yield of 10% vinegar being 100-200x the "operating volume", considering ~5/16 of this volume being drawn off daily? Using the example already given (not a 200x "supercharged" model), that's 336 x 2500 ml/yr...presumably they're cleaned and restarted once in a while. Nowhere does Frings say you need magic beans to participate. Nothing I've seen says pure cultures can be maintained or are superior to spontaneous bacteria that simply arise from the act of making vinegar, much less be sold.
Quote: Originally posted by S.C. Wack  
They didn't use pumps 200 years ago either.


Well OK Ham's 1824 patent does use liquid and air pumping, and is the Frings generator (the supported media Frings process, not to be confused with their later Acetator) over 100 years before Frings was awarded their patents for the same thing...it was not much used, which is why they're called Frings generators instead of Ham. Mostly chimney airflow and manual labor was used back in the day. It is said to take 5 days for a Frings generator to convert a charge of alcohol to vinegar batchwise, but I am not talking about using such technique. Plus, just because double and triple-run continuous technique existed (at different strengths, not unlike genuine balsamic vinegar) does not mean that the continuous single-run generator plan of which I speak (alcohol + vinegar over the top, vinegar of 0.2-0.4% ethanol falling out the bottom, not magically defying gravity for a week or two) did not exist, was not endorsed, is not wise when done correctly, or (the Frings generator technique was designed to overcome this) can be set up and operated in whichever way some idiot feels like.

macckone - 29-9-2021 at 06:41

You would be wrong on finding references and 'uncatalyzed' air oxidation is probably a misnomer but it does occur as any wine aficionado that has gotten an oxidized bottle can tell you:

https://www.google.com/search?q=fermentation+enzymatic+actio...

I would work under the assumption that any marketing material is using the most optimal conditions for its claims.

The use of acetobacter aceti m23 is well documented. There may be even better strains but that is the one I am familiar with. Maintaining pure cultures is very much a thing in industry. Obviously there are spontaneous mutations but they tend to be inferior in production compared to an optimized strain. There are literally entire books written on maintaining optimal strains of acetic acid bacteria.

S.C. Wack - 29-9-2021 at 17:25

The references which I seek are limited to those actually relevant to the topic. Such as, chemical changes in balsamic or other vinegar due to enzymes.
Quote: Originally posted by macckone  
The use of acetobacter aceti m23 is well documented. There may be even better strains but that is the one I am familiar with. Maintaining pure cultures is very much a thing in industry. Obviously there are spontaneous mutations but they tend to be inferior in production compared to an optimized strain. There are literally entire books written on maintaining optimal strains of acetic acid bacteria.


Such as?

"Acetic acid fermentation, both industrial and small scale, is always achieved with mixed cultures of acetic acid bacteria from previous batches or with indigenous bacteria present in the raw materials. The use of selected strain cultures is only an interesting research topic that is implemented because vinegar is generally a cheap commodity and also because the selective pressure changes during the fermentation process with a succession of species appearing." - Balsamic Vinegars

"The vinegar industry has traditionally worked with acetic acid bacteria which are not derived from pure cultures...It has long been known that the properties of a newly isolated strain of acetic acid bacteria may change from the very first moment of cultivation in Petri dishes, and that this strain, if cultivated over a number of generations, may show other properties, especially in its adaptation to certain concentrations of acetic acid, but also in its phenotypic features." - Ullmann's

"Vinegar production in small and large industries is performed without the use of a selected starter culture of AAB. A common practice is to use mixed AAB cultures from previous fermentation batches (backslopping practice). Selected strains are not applied in the industry for two reasons: the first reason is technological and the second reason is economical. First, the strong variation in the selective pressure between the beginning of the process and the end of the process requires the ongoing adaption of the culture. The adaptation of the culture substantially affects the processes in terms of a slowdown or stop to fermentation" - Acetic Acid Bacteria

unionised - 30-9-2021 at 11:39

Quote: Originally posted by macckone  
unionized,


Maximizing concentration would require the traditional balsamic process which can get up to 30%

How?

S.C. Wack - 30-9-2021 at 15:58

It's those zombie catalyst enzymes released by dead bacteria...BTW there's an uninteresting point to note when speaking of the acid content of traditional balsamic vinegar; it has legal definitions (in the EU or at least Italy) with a certain minimum acidity, a value expressed as so much acetic acid, by weight or volume, but this is actually derived from titration and converted to the acetic acid equivalent, i.e. it need not contain any acetic acid at all, as long as it has other acids. And in fact it is said (no surprise, really) that the acid content of the best TBV is mostly nonvolatile.

[Edited on 1-10-2021 by S.C. Wack]

macckone - 8-10-2021 at 12:46

Zombie implies enzymes are alive.
They are not.
They are organic catalysts.
Some enzymes rapidly denature, some do not.
Denaturing of enzymes is very temperature dependent.
A lot of enzymes do not denature quickly in a low oxygen environment.